Question

For a parallel RLC circuit, the incorrect statement among the following is _____________ (a) The bandwidth of the circuit decreases if R is increased (b) The bandwidth of the circuit remains same if L is increased (c) At resonance, input impedance is a real quantity (d) At resonance, the magnitude of input impedance attains its minimum value I got this question in a national level competition. Asked question is from Problems of Parallel Resonance Involving Quality Factor topic in division Resonance & Magnetically Coupled Circuit of Network Theory Select the correct answer from above options network theory questions and answers, network theory questions pdf, network theory question bank, network theory gate questions and answers pdf, mcq on network theory pdf, gate network theory questions and solutions, network theory mcq Test , ies network theory questions, Network theory Questions for GATE EC Exam, Network Theory MCQ (Multiple Choice Questions)

Answer 1

The correct choice is (d) At resonance, the magnitude of input impedance attains its minimum value The explanation is: BW = 1/RC It is clear that the bandwidth of a parallel RLC circuit is independent of L and decreases if R is increased. At resonance, imaginary part of input impedance is zero. Hence, at resonance input impedance is a real quantity. In parallel RLC circuit, the admittance is minimum, at resonance. Hence the magnitude of input impedance attains its maximum value at resonance.